Connecting structure for optical connector

ABSTRACT

An optical connector that provides a housing body  21  and a fixed part  22  that are installed so as to hold a backplane  3 , and connects an optical connector plug  4   b  inserted into said housing body  21  via an installation hole in backplane  3  and another optical connector plug  4   a  inserted into said housing body  21  from the direction opposite to that of fixed part  22  engage said housing body  21  via said installation hole  30  in said backplane  3 , and thereby said backplane  3  is held between said housing body  21  and said fixed part  22 . Simply by adjusting the floating range (amount of floating) of the flexible claws  25  within said installation hole  30  the floating range (amount of floating) of the housing body  21  can be reliably set. Thereby, when the housing body  21  engages the printed board housing, the dimensional error is offset reliably by the floating of the housing body  21 , and the engagement is carried out smoothly. A special order part for setting the floating range of the housing body  21  is not necessary, and thus a lower cost is possible and assembly can be carried out easily. In addition, a structure can also be used wherein the flexible claws projecting from the housing body side engage the backplane by passing through the installation hole, and the backplane is held between the bearing walls on the side of the housing body.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an optical connector, and in particularto an optical connector that connects together optical connector plugsinserted from the front and back of a backplane in a housing bodyinstalled by using an installation hole in the backplane of a plug-inunit, for example.

2. Description of the Related Art

What is termed a backplane connector (referred to hereinbelow as a “BPconnector”) is a plug-in type optical connector that connects opticalconnector plugs inserted into both the front and back of a backplaneusing a backplane housing (hereinbelow, a “BH housing”) assembled usingan installation hole in the backplane of a plug-in unit, for example.

FIG. 46 is an example of this BP connector.

In FIG. 46, reference numeral 1 is a plug-in unit, reference numeral 2is a printed board, reference numeral 3 is a backplane, referencenumerals 4 a and 4 b are connector plugs (hereinbelow, “MPO plugs”),reference numeral 5 is a printed board housing (hereinbelow, “PHhousing”), and reference numeral 6 is a BH housing.

The MPO connectors 4 a and 4 b are optical connectors specified in JIS C5982 and IEC 1754-7, and having a structure that supports an opticalconnector ferrule 4 c, whose end has been PC (Physical Contact)polished, in a plastic housing.

This BP connector is assembled by engaging a PH housing 5 in a BHhousing 6 installed in a backplane on the side of a plug-in unit 1 byinserting a printed board 2 that anchors the PH housing 5 to the plug-inunit 1. The engaged PH housing 5 and the BH housing 6 form the opticalconnector adapter 7, and connect the MPO plugs 4 a and 4 b inserted fromboth sides. The MPO plug 4 a, inserted into the optical adapter 7 fromthe PH housing 5, is inserted in advance into the PH housing 5, and atthe same time that the printed board 2 is inserted into the plug-in unit1, the optical connector adapter 7 is inserted. On the plug-in unit 1, aplurality of printed boards 2 can be accommodated in parallel at a highpacking density, and thus high-density packing of optical connectoradapters 7 is possible with this BP connector.

FIG. 47 is an exploded perspective drawing showing the BH housing 6.

As shown in FIG. 47, the BH housing 6 provides a housing body 8 and abackside housing 9 that are disposed opposite each other via thebackplane 3. The housing 8 is disposed on the printed board 2 side (theleft side in FIG. 7), and the backside housing 9 is disposed at aposition facing the housing body 8 via the backplane 3. Pins 10 projectfrom the housing body 8, pass through to the opposite side of thebackplane 3 by being inserted through the installation hole 11 in thebackplane 3, and anchor the backside housing 9 to the protruding ends ofthe pins 10 by screws 12.

FIG. 48 shows the installation hole 11.

As shown in FIG. 48, the installation hole 11 is rectangular, and has anextended part 13 in the four corners. The pins 10 are accommodated inthe opposing pairs of extended parts 13 and 13 along the diagonal(omitted from figure) of the installation holes 11, and furthermore, inthe vertical direction (top to bottom in FIG. 48), a gap 14 ofapproximately a=1.60 mm is maintained, and in the horizontal direction(left to right in FIG. 48), a gap 15 of approximately b=0.34 mm ismaintained. The housing body 8 and the backside housing 9 slidably holdthe backplane 3, and thus the BH housing 6 can float within the range ofmovement of the pins 10 and 10 in the gaps 14, 15. Thereby, as shown inFIG. 46, when the PH housing 5 is engaged in the BH housing 6 the sizediscrepancy is offset by the floating of the BH housing 6, and thus theengagement operablity is improved.

Specifically, in the abutment connection between the optical connectorferrules 4 c, 4 d defined in JIS C 5981, one optical connector ferrule 4c is engaged in advance, the guide pins 4 p projecting from the junctionend are inserted and engaged in the guide pin holes 4 q bored into theother optical connector ferrule 4 c, and thereby precisely positioned.When the PH housing 5 has been properly engaged, the guide pins 4 p canbe smoothly engaged in the guide pin holes 4 q due to the floating ofthe BH housing 6.

However, in the case of this BP connector, the dimension of the screw 12diameter is about 1.2 mm, labor is involved in anchoring the backsidehousing 9 with a hand tool, and thus its operability is notsatisfactory. In particular, when applying this BP connector to the wallof a building, etc., there are many cases in which an adequate workspace cannot be secured, and this problem of operability becomes evenmore serious. In addition, because the screw 12 itself is a specialorder item, cost reductions are difficult, and at the same time, becausethe pin 10 and screw hole 16 (refer to FIG. 47) are formed conforming tothe screw 12, there is the problem that labor is involved in theirmanufacture. Furthermore, because the installation hole 11 formed in thebackplane 3 acquires a complicated shape corresponding to the screws 12,there is the problem that labor is involved in the formation of thisinstallation hole 11. If the floating range of the BH housing 6 is toobig or too small, ensuring the engagement of the PH housing 5 isdifficult, and thus even more care is required in the formation of thescrew 12, the pin 10, and the installation hole 11, which involveslabor.

SUMMARY OF THE INVENTION

In consideration of the above, it is an object of the present inventionto provide an optical connector that can be assembled simply, andfurthermore does not require screws for anchoring, and makes possiblethe reduction of cost by reducing the number of parts by engagingflexible claws projecting from an anchoring part disposed opposite ahousing body via the backplane in this housing body via an installationhole in this backplane, or engaging flexible claws projecting from aninstallation part attached to the outside of the housing body on thisbackplane via the installation hole.

The present invention is an optical connector providing a housing bodyand a fixed part that are disposed on opposite sides of the backplane,and installed so as to hold this backplane, and via an installation holein the backplane, connect an optical connector plug inserted in thehousing body and a separate optical connector plug inserted into thehousing body from the direction opposite to this optical connector plug,and wherein this fixed part provides a plug insertion hole in which thisoptical connector plug is inserted, and flexible claws that engage bybeing disposed on opposite sides of the plug insertion hole and theninserted into the housing body. These flexible claws are installed sothat the housing body and the fixed part hold the backplane by beingengaged in the housing body via the installation hole in the backplane.In addition, the plug insertion hole communicates with the installationhole and the housing body to form a means to solve the above-describedproblems.

This optical connector is installed by holding the backplane between thehousing body and the fixed part by engaging the flexible claws of thefixed part in the housing body via an installation hole in thebackplane. In addition, the flexible claws can be structured so as to bedetachable from the housing body, and thereby the removal operability isimproved.

For example, as disclosed in the description of related art, inconsideration of the structure in which a printed board housing attachedto a printed board inserted in a plug-in unit is engaged in a housingbody, the housing body is allowed to float. When the desired floatingrange is reliably attained for the housing body, the misalignment can beoffset by the floating range of the housing body when the print porthousing is engaged in the housing body, and thus the engagementoperability is improved.

Thus, in the present invention, in order to attain reliably the desiredfloating range for the housing body, as recited in Claim 2, a structureis generally adopted that permits displacement of the flexible claw inthe installation hole by securing a clearance in the vicinity of theflexible claws inserted in the installation hole by a structure whereinthe flexible claws of the fixed part passe through the installation holein the backplane and is engaged in the housing body. According to thisstructure, the housing body and the fixed part, which are assembled byenclosing the backplane by the engagement of the flexible claw, form abackplane housing that can integrally float within the range of movementof the flexible claw in the installation hole. Therefore, by simplysetting the range of movement of the flexible claw in the installationhole, the amount of floating of the backplane housing can be easily set,and the desired floating range or amount of floating in the housing bodycan be reliably attained. Thereby, in order to set the floating range oramount of floating of the housing body, it is unnecessary to prepareseparately a special order part, and the cost can be reduced.

In addition, as recited in claim 15, with the present invention, astructure can also be used wherein the housing body is supported at thedesired position in the backplane by the pair of flexible claws,projecting from the installation part mounted and anchored outside thehousing body, engaging the backplane on both sides of this engaging holeby passing them through the installation hole in the backplane, andholding the backplane between the pair of flexible claws and thesupporting wall provided on the installation part.

In this structure, the backplane housing that comprises the housing bodyand the installation part is supported by both the outside and inside ofthe backplane. Moreover, due to the clearance guaranteed in the vicinityof the flexible claws inserted in the installation hole, the point thatthe desired floating range and the amount of floating of the housing canbe easily and reliably attained, and the point that the desired floatingrange and amount of floating can be set without special order parts, arethe same as described above.

Moreover, below, backplane connector is abbreviated “BP connector”,backplane housing is abbreviated “BH housing”, and printed board housingis abbreviated “PH housing”.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1 shows the first embodiment of the optical connector of thepresent invention, and is an exploded perspective drawing showing the BHhousing.

FIG. 2 is a perspective drawing showing the assembled state of the BHhousing in FIG. 1.

FIG. 3 is a frontal drawing showing the installation hole with the BHhousing of FIG. 1 installed.

FIG. 4 is a frontal drawing showing the clearance that is guaranteed inthe vicinity of the flexible claws in the installation hole of FIG. 3.

FIG. 5A is a planar drawing showing the internal housing; FIG. 5B is afrontal drawing (the PH housing side) showing the internal housing; FIG.5C is a side drawing showing the internal housing; FIG. 5D is a planecross-section showing the internal housing; FIG. 5E is a back view (thebackplane side) showing the internal housing; and FIG. 5F is a sidecross-sectional drawing showing the internal housing.

FIG. 6A is a planar cross-sectional drawing showing the PH housingbefore engaging the BH housing; FIG. 6B is a side cross-sectionaldrawing of the same.

FIG. 7A is a planar cross-sectional drawing showing the MPO plugs duringengagement; FIG. 7B is a side view thereof; FIG. 7C is an enlarged sidecross-sectional drawing showing the deformed state of a claw of the PHhousing.

FIG. 8A is a planar cross-sectional drawing showing the external engagedstate of the PH housing with respect to the BH housing; FIG. 8B is aside cross-sectional drawing thereof; FIG. 8C is an enlarged sidecross-sectional figure showing the engaged state of one of the claws ofthe PH housing and an external projection of the housing body.

FIG. 9A is an enlarged planar cross-sectional drawing showing therelease of an engagement between an engaging claw of the internalhousing and an engaging projection of the housing body; FIG. 9B is aplanar cross-sectional drawing; FIG. 9C is a side cross-sectionaldrawing showing the release of the engagement between the engaging clawsof the internal housing and the engaging projections of the housing bodyby the pressing projections of the housing body.

FIG. 10A is a planar cross-sectional drawing showing the final state ofthe engagement of the PH housing with respect to the BH housing; FIG.10B is a side cross-sectional drawing thereof.

FIG. 11 is a perspective drawing showing the fixed part having a curvedspring part such that the peak is positioned at the center of bothflexible claws.

FIG. 12 is a perspective drawing showing the assembled state of the BHhousing using the fixed part in FIG. 11.

FIG. 13 is a side view showing the fixed part in FIG. 12.

FIG. 14 is a perspective drawing showing the fixed part having an angleshaped spring part is angled such that the peak is positioned at thecenter of both flexible claws.

FIG. 15 is a perspective drawing showing the fixed part having an angleshaped spring part extending uniformly between both flexible claws.

FIG. 16 is an exploded perspective drawing showing a BH housing usingthe internal housing provided with a projecting wall for reinforcement.

FIG. 17 is a perspective drawing showing the assembled state of the BHhousing in FIG. 16.

FIG. 18 is a drawing viewing the internal housing of FIG. 16 from thebackplane side.

FIG. 19 is a drawing viewing from the opposite side the state of theinternal housing of FIG. 16 engaged in the housing body from the sideopposite the backplane.

FIG. 20 is a perspective drawing showing the PH housing.

FIG. 21 is a side cross-sectional drawing showing the operation of theengagement of the PH housing and the BH housing in FIG. 16.

FIG. 22 is a side view showing the optical connector (BP connector)using the simplified PH housing directly accommodating an opticalconnector ferrule.

FIG. 23 is a perspective drawing showing the PH housing in FIG. 22.

FIG. 24 is a side cross-sectional drawing showing the PH housing in FIG.22.

FIG. 25 is a side view showing the optical connector (BP connector)using the PH housing whose installation structure on the printer boardhas been improved.

FIG. 26 is an exploded perspective drawing showing the PH housing inFIG. 25 and the rivet parts.

FIG. 27 is a front view showing the PH housing in FIG. 25.

FIG. 28 is a planar drawing showing the PH housing in FIG. 25.

FIG. 29 is an exploded perspective drawing showing a different PHhousing whose installation structure on the printer board has beenimproved.

FIG. 30 is a planar drawing showing the PH housing in FIG. 29.

FIG. 31 is an exploded perspective drawing showing the PH housing usingthe fixed part having the constricted part formed part of the way alongthe flexible claws.

FIG. 32 is a perspective drawing showing the assembled state of the BHhousing in FIG. 31.

FIG. 33A is a side cross-sectional drawing showing the fixed part of theBH housing in FIG. 32.

FIG. 33B is a bottom view showing the fixed part of the BH housing inFIG. 32.

FIG. 33C is a side drawing viewing the housing body of the BH housing inFIG. 32 from the backplane side.

FIG. 34 is an exploded perspective drawing showing the optical connector(backplane connector) using the internal housing having projectionsextending on the side as a positioning part.

FIG. 35 is a planar cross-sectional drawing showing the state of theinternal housing in FIG. 32 inserted into the housing body.

FIG. 36 is a drawing showing the second embodiment of the presentinvention, and is an exploded perspective drawing showing a BH housingusing a fixed part having a structure in which the flexible claws engagefrom the outside the engaging parts on both sides of the housing body.

FIG. 37 is a perspective drawing showing the assembled state of the BHhousing in FIG. 36.

FIG. 38 is an enlarged drawing showing the engagement operation of theflexible claws of the fixed part with respect to the engaging part ofthe housing body.

FIG. 39 is a front view showing the clearance secured in the vicinity ofthe flexible claw in the installation hole the pack plane.

FIG. 40 is a drawing showing the third embodiment of the presentinvention, and is an exploded perspective drawing showing a BH housingwherein the flexible claws projecting from the installation partintegrally attached to the housing body is installed by engagement withthe installation hole in the backplane.

FIG. 41 is a perspective drawing showing the assembled state of the BHhousing of FIG. 40.

FIG. 42 is a perspective drawing showing the installation part of the BHhousing of FIG. 40.

FIG. 43 is a planar drawing showing the installation state with respectto the backplane of the installation part in FIG. 42.

FIG. 44 is a front view showing the clearance that is guaranteed in thevicinity of the flexible claws in the installation hole in thebackplane.

FIG. 45 is an exploded drawing showing the BH housing wherein theflexible claws projecting from the housing body are installed byinsertion engagement into the installation hole in the backplane.

FIG. 46 is an exploded perspective drawing showing the BP connector inthe background art of the present invention.

FIG. 47 is an exploded perspective drawing showing the BH housing of theBP connector in FIG. 46.

FIG. 48 is a front view showing the installation hole of the BPconnector in FIG. 46.

PREFERRED EMBODIMENTS OF THE INVENTION

Below, the first embodiment of the optical connector of the presentinvention is explained referring to the figures.

The optical connector (BP connector) shown in FIG. 1 and FIG. 2comprises the BH housing shown by reference numeral 20 in FIG. 1 andFIG. 2. This BH housing 20 forms an optical connector adapter thatconnects together the MPO plugs 4 a and 4 b (corresponding to theoptical connector plug recited in claim 1) inserted from both sides byengaging the PH housing 5 shown in FIG. 46.

Moreover, structural components identical to those of FIG. 46 to FIG. 48have the identical reference numerals, and the explanation of these hasbeen omitted.

As shown in FIG. 1 and FIG. 2, the BH housing 20 provides a housing body21 and a fixed part 22 (or a fixed metal fitting).

As shown in FIG. 1, the housing body 21 is formed as a square sleevefrom a synthetic resin such as plastic, and provides a plugaccommodation hole 23 that accommodates the inserted MPO plugs 4 a and 4b. In the plug accommodation hole 23, the internal housing 21 a isaccommodated, and the internal housing 21 a positions the MPO plugs 4 aand 4 b connected therein so as to be able to form an abutmentconnection through the key groove 21 b. Moreover, the internal housing21 a is accommodated by allowing a slight floating in the axialdirection of the housing body 21, but is precisely positioned in allother directions. In addition, even during the process of accommodationin the housing body 21, the internal housing 21 a is structured so as tobe able to move in the axial direction of the housing body 21. This willbe described in detail below.

The fixed part 22 is formed entirely from an flexible material, and hasa C-shape providing a frame-shaped body 24 and a pair of flexible claws25 and 25 that project form both sides of the body. The projectionpositions of the flexible claws 25 and 25 conform to the pair of longrectangular engaging holes 26 and 26 formed on both sides (vertically inthe figure) opposite to the housing body 21 (an engaging hole 26 is alsoon the lower side of the housing body 21 shown in FIG. 1 and FIG. 2). Inaddition, an engaging claw 27 projects from the ends of the flexibleclaws 25 and 25. In FIG. 2, the engaging claws 25 and 25 are insertedthrough the installation hole 30 in the backplane 3, respectivelyinserted into the engaging holes 26 and 26 of the housing body 21disposed on opposite sides via the backplane 3, and engage the engagingclaws 27 at the engaging parts 28 and 28 of the housing body 21.

As shown in FIG. 3, the installation hole 30 is rectangular, and extendsin the form of a slit in the backplane 3. The dimension of the lateralwidth (in the horizontal direction in the figure) of the body 24 of thefixed part 22 is at least larger than the lateral width of theinstallation hole 30, and the plug insertion hole 29 at the center ofthe body 24 is smaller than the insertion hole 30. Furthermore, thelateral width of both flexible claws 25 and 25 is smaller than thelateral width of both installation holes 26 and 26. As shown in FIG. 2,in the assembled BH housing 20, the backplane 3 is gently held betweenthe housing body 21 and the body 24 by a clamping force that allowssliding.

As a result, as shown in FIG. 3, a clearance is guaranteed in thevicinity of the flexible claws 25 and 25 inserted into the installationhole 30, and within the installation hole 30, deformation of theflexible claws 25 and 25 and movement of position is allowed within therange of this clearance. Therefore, on the BH housing 20 installed inthe backplane 3, floating of the flexible claws 25 and 25 within therange of movement in the installation hole 30 is allowed. For example,as shown in FIG. 4, this clearance is guaranteed to be c=0.34 mm in thehorizontal direction (left to right in FIG. 4) and d=1.60 mm in thevertical direction (top to bottom in FIG. 4), and within the range ofthis clearance, the flexible claws 25 and 25 can shift, and the range offloating and the amount of movement with respect to the backplane 3 ofthe BH housing 20 can be set. Thereby, when the printed board 2 isinserted into the plug-in unit 1 (refer to FIG. 46) and the PH housing 5is engaged in the BH housing 20, even when the positioning between thePH housing 5 and the BH housing 20 is misaligned, by forcibly pressingthe PH housing towards 5 the BH housing 20, the PH housing 5 will engagethe BH housing 20. That is, the misalignment of these housings 5 and 20is offset by the floating of the BH housing 20, and thus the engagementoperability is improved. Thereby, in the case that both MPO plugs 4 aand 4 b are connected at the same time the PH housing 5 and the BHhousing 20 are engaged, the operation of inserting and engaging theguide pin 4 p of one optical connector ferrule 4 c into the guide pinhole of the other optical connector ferrule 4 c also can be carried outsmoothly.

In assembling this BH housing 20 in the backplane 3, the housing body 21is disposed adjacent to the desired installation hole 30 at the insideof the plug-in unit 1 (refer to FIG. 46), and the flexible claws 25 and25 of the fixed part 22 are inserted into the engaging holes 26 and 26of the housing body 21 through the installation hole 30 from the outsideof the plug-in unit 1 (further to the right than the backplane in FIG.1). The engaging holes 26 and 26 form a vertical slit having a narrowlongitudinal width (the top to bottom direction on the surface of thepage). The width (longitudinal width) of this slit is larger than thethickness of the flexible claws 25, and in addition, is smaller than thesum of the height of the flexible claw 25 and the engaging claw 27. Thetransverse width of the slit is larger than the transverse width of theflexible claw 25. Thus, when the flexible claw 25 is inserted into theengaging hole 26, the engaging claw 27 abuts the engaging hole 26. Thatis, the engaging claw 27 is a cantilever-type flexible body made bystamping and bending the end of the flexible claw 25, and when forciblyinserted into the engaging hole 26, is flexibly deformed by the engaginghole 26 by gradually bending. Furthermore, when inserted, the engagingclaw 27 passes through the engaging hole 26, and is restored to itsoriginal shape by its elasticity. When the shape of the engaging claw 27is restored after passing through the engaging hole 26, the free end ofthe engaging claw 27 engages with one part of the BH housing on theupper side of the engaging hole 26. Thereby, the extraction of theflexible claw 25 from the engaging hole 30 is restricted, and theintegration of the fixed part 22 and the BH housing 20 is complete.

Therefore, the operation of mounting this BH housing 20 into thebackplane 2 comprises simply pressing the fixed part 22 into the housingbody 21, and thus in comparison to anchoring using pins, the operabilityis improved. In addition, in contrast to the anchoring by a pin, whichrequires a work space for the screw anchoring, the work space is reducedbecause only a space sufficient for a hand to enter in order to pressthe fixed part 22 needs to be secured, and this is advantageous in thecase of carrying out this work on the wall of a building, etc. With thisoptical connector, the BH housing 20 can also be assembled by pressingthe housing body 21 into the fixed part 22, which has been anchored inadvance, and in this case, it is not necessary to secure a work spaceoutside the plug-in unit.

In addition, simply by adjusting the shape of the flexible claws 25 and25, the clearance in the vicinity of the flexible claws 25 and 25inserted in the installation hole 30 can be easily adjusted, and thusthe floating range of the BH housing 20 can be easily set. Thereby,because the shape of the installation hole 30 can be simple and therequired precision can be eased, the formation operability can beimproved.

Furthermore, there is also the effect that the cost can be reduced sincethe number of parts is reduced because pins are not used.

Next, the structure of the internal housing 21 a will be explained.

The internal housing 21 a is an integral part formed by a resin mold,and as shown in FIG. 1, the engaging claws 21 d on both sides of theinternal housing 21 a are inserted into the engaging groove 21 m on bothsides inside the housing body 21. As shown in FIG. 5A to FIG. 5E, theengaging claws 21 d are flexible claws providing an engaging end 222 onthe end of the L-shaped arm part 221 projecting from both sides of theinternal housing 21 a. In addition, as shown in FIG. 5A, this internalhousing 21 a is inserted into the housing body 21 from the backplane 3side (the right side in FIG. 5A), and thereby the engaging claws 21 dthat move along the engaging grooves 21 m in the direction of the PHhousing 5 (the left side in FIG. 5A) engage the engaging projection 21 nprojecting in the engaging groove 21 m (specifically, the engaging end222 is engaged by being hooked). Thereby, the internal housing 21 a isstopped temporarily in the housing body 21, and the movement of theinternal housing 21 a in the direction of the backplane 3 is restricted.That is, even when the internal housing 21 a is pressed from the leftside to the right side in the figure, the internal housing 21 a is notseparated from the housing body 21, and the engagement with the engagingprojection 21 n is not easily released. Meanwhile, when pressed from theright to the left side in the figure, as shown in FIG. 5F, the separateexternal projections 21 p projecting on both the top and bottom sides ofthe internal housing 21 a (top to bottom in FIG. 5F) are abutted so asto contact the restricting projection 210 projecting on the innersurface of the housing body 21, and thereby the internal housing 21 a isnot moved any further in the direction of the PH housing 5 (the leftside of FIG. 5A). In this manner, the internal housing 21 a istemporarily stopped, and in the left to right direction in the figure,slight movement is possible between the engaging projection 21 n and therestricting projection 21 o. Moreover, the positioning projection 21 cthat extends along the side surface of the internal housing 21 a fromthe external projection 21 p slides along with the wall inside thehousing body 21, and misalignment of the internal housing 21 a in anydirection other then the axial direction of the housing body 21 isprevented.

The lock projection 223 projecting on the side of the backplane 3 of theinternal housing 21 a, as shown in FIG. 6B, is engaged detachably withthe engaging part 4 j formed on the housing 4 i of the MPO plug 4 binserted into this internal housing 21 a.

As shown in FIGS. 6A and 6B, when the MPO plug 4 b is inserted into theinternal housing 21 a via the installation hole 30 of the backplane 30,the end of the coupling 4 d of the MPO plug 4 b abuts the end of thebackplane 3 side of the internal housing 21 a. By pressing further, whenthe housing 4 i reaches its sliding limit with respect to the coupling 4d, pressing of the housing 4 i any further is restricted. In addition,by the lock projection 223 of the internal housing being detachablyengaged in the engaging part 4 j of the housing 4 i of the MPO plug 4 b,the MPO plug 4 b is detachably fastened.

Next, the connection between the MPO plugs 4 a and 4 b in this BPconnector will be explained in detail.

As shown in FIG. 7A, FIG. 7B, and FIG. 7C, when the PH housing 5 isengaged in the BH housing 20 assembled with the MPO plug 4 b inserted inadvance, first, the insertion and engagement of the guide pins 4 p intothe guide pin holes 4 q is carried out via the optical connectorferrules 4 c at the ends of the MPO plugs 4 a and 4 b, and thecontacting end surfaces of the optical connector ferrules 4 c arecorrectly positioned with each other, and abutted. At this time, theclaws 5 a and 5 b on both sides of the PH housing 5 ride over theexternal projections 21 p projecting from the outside of the housingbody 21, and are pushed apart so as to separate from each other.

Next, as shown in FIG. 8A, FIG. 8B, and FIG. 8C, as further insertion ofthe PH housing 5 into the BH housing 20 continues, the claws 5 a and 5 bof the PH housing 5 respectively engage the external projections 21 p ofthe housing body 21. At this time, the extraction of the PH housing 5 inthe rearward direction (the left side in the figure) is restricted, andat the same time, in FIG. 8C, the PH housing 5 is allowed to shiftwithin the concavity p.

Next, as shown in FIG. 9A, FIG. 9B, and FIG. 9C, as further insertion ofthe PH housing 5 into the BH housing 20 continues, the pressingprojection 5 c that projects from the PH housing 5 is inserted along thewall inside the housing body 21, and thereby the engaging claws 21 d ofthe internal housing are separated from the adjacent wall in the housingbody 21, and the engagements between the engaging claws 21 d and theengaging projections 21 n is released. Until this time, due to theengagement of the engaging claws 21 d and the engaging projections 21 n,the condition of the accommodation of the internal housing 21 a in thehousing body 21 is stable, but when the engagement is released due tothe pressing projection 5 c, the movement of the internal housing 21 awithin the housing body 21 becomes free, and the misalignment betweenthe MPO plugs 4 a and 4 b can be offset with high efficiency. At thistime, the shifting within the range of the concavity p also contributesto offsetting the misalignment between the MPO plugs 4 a and 4 b. At theMPO plugs 4 a and 4 b, due to the spring built into the housing 4 i, theoptical connector ferrule 4 c is urged in the forward direction of theabutment connection, and thus, when the optical connector ferrules 4 cand 4 c of both MPO plugs 4 a and 4 b abut each other, the tensile forceof this spring acts as a force to bring about abutment between theoptical connector ferrules 4 c and 4 c, and the state of the connectionbetween optical connector ferrules 4 c and 4 c is stabilized, and a lowconnection loss is reliably obtained.

In addition, finally the state shown in FIG. 10A, FIG. 10B, and FIG. 10Cis attained.

The above-described connection process and the relationship between theinternal housing 21 and the PH housings, etc., are the same for each ofthe concrete examples described below, and even in the concrete exampleswherein the structure of the PH housing has been altered, therelationship is fundamentally the same.

Moreover, the above-described shape of the housing body 21, the internalhousing 21 a, the fixed part 22, and the PH housing 5, etc., are notlimiting, and as appropriate, or course the design can be changed.

For example, the fixed part more preferably uses a structure providing aspring between both flexible claws 25 and 25.

The fixed part 22 a shown in FIG. 11, FIG. 12, and FIG. 13 joins betweenboth the flexible claws 25, and a spring part 31 is formed on the body24 extending to both sides opposite the plug insertion hole 29. Thereference numeral 20 a is the BH housing, which is formed by the housingbody 21, the internal housing 21 a, and the fixed part 22 a.

In FIG. 11, the spring part 31 is a curved part that is formed byimparting a curve to the body 24 between both flexible claws 25, 25. Asshown in FIG. 12 and FIG. 13, when the flexible claws 25 and 25 areinserted into the installation hole 30 and then engaged in the housingbody 21, the spring part 31 abuts the backplane 3, and the backplane 3is held between the housing body 21 and the spring part 31. In addition,within the range of flexible deformation of the spring part 31, theoperability of the engagement with the PH housing 5 can be improvedbecause the error in the thickness dimension of the backplane is offset,the installation state of the housing body 21 is stable, andfurthermore, the desired floating range due to the clearance shown inFIG. 4 is obtained in the housing body 21.

In the case that the thickness dimension of the backplane 3 is largerthan a specified dimension, when the flexible claws 25 and 25 of thefixed part 22 a are pressed into the engaging hole 26 of the housingbody 21 from the installation hole 30, the spring part 31 abutting thebackplane 3 is flexibly deformed by the pressing force, and thereby theflexible claws 25 and 25 can be engaged in the engaging parts 26 and 26of the housing body 21. Contrariwise, even in the case that thethickness dimension of the backplane 3 is smaller than a specifieddimension, because the error in the dimension of the backplane 3 isoffset by the flexible deformation of the spring part 31, the occuranceof an excessive gap between the fixed part 22 a and the housing body 21can be prevented, and in the housing body 21, the desired floating rangecan be reliably attained due to the range of movement of the flexibleclaws 25 and 25 within the installation hole 30. By thus preventingfloating of the housing body 21 beyond what is necessary, the operationof engaging the PH housing 5 can be carried out with high efficiency.

In the fixed part 22 b shown in FIG. 14, a spring part 32 is formed inwhich the body 24 that extends on both sides of the plug insertion hole29 so as to join both flexible claws 25 and 25 is bent at an angle. Thisspring part 32 has a peak 33 in the center in the longitudinal direction(top to bottom in FIG. 14) of the long frame shape of the body 24, thatis, at the center between the flexible claws 25 and 25. When the BHhousing 20 b is assembled so that the backplane 3 is held by the housingbody 21 and the fixed part 22 b, the contact part of the spring part 32with the backplane 3 is only the peak 33, and thus the slidingresistance between the backplane 3 and the spring part 32 can besignificantly reduced, and the housing body 21 can slide more freely.

The spring part 34 of the fixed part 22 c shown in FIG. 15 is a bentpart, wherein the body 24, extending on both sides of the plug insertionhole 29 so as to join both flexible claws 25 and 25, is bent at an anglethat extends over between the flexible claws 25 and 25. Therefore, whenthe BH housing 20 c is assembled by enclosing the backplane 3 by thehousing body 21 and the fixed part 22 c, the entire peak 35 extendingalong the whole length of the spring part 34 abuts the backplane 3, thecontact area with the backplane 3 is sufficiently guaranteed, and theelasticity can act stably. Because the elasticity can be sufficientlyguaranteed with this spring part 34, when the PH housing 5 is engagedwith the housing body 21, it is preferably used when a large force isacting.

Moreover, the spring part is not limited to one which forms the body ofthe flexible part, and a flat spring or a coil spring mounted in thefixed part can also be used.

Next, an example of the structure of the internal housing will beexplained.

The sleeve shaped internal housing 211 having a positioning projection21 c and a projection wall 21 e projecting on its four corners isinserted in the housing body 12 that forms the BH housing 20 d shown inFIG. 16 and FIG. 17. In the BH housing 20 d the backplane 3 is heldbetween the housing body 21 and the fixed part 22 a, and the differencebetween this and the BH housing 20 a shown for example in FIG. 11 is theuse of the internal housing 211.

FIG. 18 is a drawing of the internal housing 211 viewed from thebackplane 3 side.

As shown in FIG. 18, this positioning projections 21 c are provided onboth ends of the external projections 21 p in the direction extendingparallel to each other on both the upper and lower ends (top to bottomin FIG. 18) of the internal housing 211. Adjacent to each positioningprojection 21 c, a projecting wall 21 e projects. The projecting wall 21e is a small wall that projects towards the positioning projection 21 con the opposing side vertically from the positioning projection 21 c,and as shown in FIG. 19, when the internal housing 221 is inserted intothe housing body 21, its outer surface abuts the wall surface in thehousing body 21.

In addition, in the internal housing 211, by being held between thepositioning projection 21 c and the projecting wall 21 e, a double-wallaccommodation groove is formed. When the PH housing 36 (refer to FIG.20) is engaged into the BH housing 20 d, the double wall 36 a projectingon the PH housing 36 is inserted.

FIG. 20 is a perspective drawing showing the PH housing 36 of theoptical connector in the embodiment of the present invention.

In FIG. 20, on both sides of the PH housing 36, a pair of release claws36 b and 36 b that can be disengaged from the housing body 21 aredisposed opposite each other. In addition, a supporting wall 36 c isprovided on the inside of the PH housing 36. The supporting wall 36 chas a sleeve shape, and the MPO plug 4 a supported in the PH housing 36is positioned and accommodated in this supporting wall 36 c. Inaddition, the double wall 36 a projects on the end of the PH housing 36in the direction of insertion into the BH housing 29 d (right to left inFIG. 20). When the PH housing 36 is inserted into the internal housing211, the double wall 36 a can be inserted into the double walledaccommodating grove 21 f. When the supporting wall 36 c abuts theengaging claw 21 d, the MPO plug 4 a accommodated and supported in thePH housing 36 is inserted at a specified position of the housing body21, and connects by abutment with the MPO plug 4 b inserted from theside opposite to the housing body 21 (the installation hole 30 side).

Because the shape of the double wall 36 a conforms almost completelywith that of the double walled accommodation groove 21 f, the doublewall 36 a that is inserted into the double walled accommodation groove21 f (refer to FIG. 19) is placed over the projecting wall 21 e withoutcausing a gap, and thus an integral wall is formed. Therefore, becausethe internal housing 211 is supported at a specified position by thehousing body 21 and this double wall 36 a, even when lateral tensileforce (what is termed “side-pull”) on the MPO plugs 4 a and 4 b acts,the deformation resistance force of the housing part 21 towards this isgreatly increased, and thus the internal housing 211 is stably supportedat a specified position. Further, inconveniences such as deformation andfracturing of the housing body 21 and the internal housing 211 can beprevented.

In addition, as shown in FIG. 21, when the PH housing 36 is engaged withthe housing body 21 (at this time, the double wall 36 a is inserted intothe double walled accommodating groove 21 f, not shown in FIG. 21), andthe supporting wall 36 c abuts the projecting wall 21 e (not shown inFIG. 21), the deformation resistance force of the housing body 21 isimproved by the supporting wall 36 c engaging in the housing body 21,and thus the deformation resistance force of the housing body 21 to thetensile force in the lateral direction can by significantly improved,and the precision of the positioning of the MPO plugs 4 a and 4 b over along period of time can be maintained.

When the deformation resistance force of the housing body 21 is improvedby the supporting wall 36 c engaging in the housing body 21, even if thetensile force acts on the MPO plugs 4 a and 4 b in the lateraldirection, the precision of the positioning can be maintained over along period of time. Concretely, because the connection between the MPOplug 4 a and 4 b is carried out by an abutment connection between theoptical connector ferrules 4 c with the ends of the MPO plugs 4 a and 4b, misalignment between the optical connector ferrules 4 c in a state ofabutment connection can be reliably prevented by preventing deformationof the housing body 21. Thereby, no shifting of the connection statebetween the MPO plugs 4 a and 4 b occurs, and a desired low connectionloss can be reliably maintained.

With this optical connector, any type of structure for a PH housing canbe used: the type of PH housing 40 that directly accommodates theoptical connector ferrule 43 as shown in FIG. 22 to FIG. 24, the PHhousings 401, 58, etc, that have superior installation properties for aprinted board 2, as shown in FIGS. 25 to 30, etc.

The entire PH housing 40 shown in FIG. 22 is made of a resin such asplastic, and can be detachably engaged with the housing body 21 of thePH housing 20 a assembled on the backplane 3. In FIG. 22, the exampleapplying the PH housing 20 a illustrated in FIG. 11 to FIG. 13 is shown,but this is not limiting, and any type of structure for the adopted BHhousing 20, such as that disclosed in FIG. 1, can be used.

Moreover, reference numeral 49 in FIG. 22 is an installation part forinstalling the PH housing 40 on the printed board 2.

FIG. 23 is a perspective drawing showing the PH housing 40, and FIG. 24is a cross-sectional drawing showing its interior.

As shown in FIG. 23, on both sides of the PH housing 40, release claws41 and 41 that can be detachably engaged with the housing body 21 areprovided. In addition, on the front part of the PH housing 40 in thedirection of the engagement and insertion into the housing body 21, aguide projection 42 that is inserted into this housing body 21 projects.

As shown in FIG. 24, in the interior of the PH housing 40, a plugaccommodation groove 44 that accommodates an optical connector plug 43(optical connector ferrule) stipulated by JIS C 5981 is provided. Thisplug accommodation groove 44 has an accommodation groove opening 45 onthe side opposite to the direction of the engagement and insertion ofthe PH housing 40 into the housing body 21, and flexibly deformablesupport claws 46 project to engage and support the optical connectorplug 43 accommodated in this plug accommodation groove 44 adjacent tothe accommodation groove opening 45. On the optical connector plug 43,the guide pins 43 b that position the optical connector plugs 4 b withthe optical connector ferrules 4 c on the same side of the connectionare engaged and maintained in a state projecting from the abutment endside 43. Furthermore, with this abutment end surface 43 a, the pin clamp43 c that holds the guide pins 43 b is installed at the opposite backend.

With this PH housing 40, while flexibly deforming the supporting claws46, this optical connector plug 43 with the pin clamp 43 c attached canbe pressed from the accommodation groove opening 45 to the plugaccommodation groove 44. In addition, because the optical connector plug43 that is pressed into the plug accommodation groove 44 is held betweenthe supporting wall 47 and the supporting claw 46 formed in the PHhousing 40, the desired positioning in the plug accommodation groove 44can be stably supported.

When the optical connector plug 43 that can terminate with the opticalfiber 48 (optical fiber core) in an abutment connection manner isinserted into the plug accommodation groove 44, the optical fiber 48 canbe extracted from this accommodation groove opening 45.

Moreover, the optical fiber that terminates in the optical connectorplug 43 can be either single or multi-core.

The optical connector plug 43 that is accommodated in the plugaccommodation groove 44 abuts the support wall 47, and thereby theprojection in the forward direction towards the engagement and insertionof PH housing is set. Therefore, in the housing body 21 (refer to FIG.22), when the optical connector plug 43 connected to the opticalconnector ferrule 4 c on the MPO plug 4 b side is extracted, theinconvenience of this optical connector plug 43 falling out of the plugaccommodation groove 44 can be prevented, and the extraction operationcan be carried out with high efficiency. In addition, as shown in FIG.24, the support claw 46 sets the movement limit of the optical connectorplug 43 away from the direction of engagement and insertion, and at thesame time, when abutment connected with the optical connector ferrule 4c, the abutment force of the MPO plug 4 b side is borne thereby.

Moreover, the connection end surface 43 a of the optical connector plug43 accommodated in the plug accommodation groove 44 is always exposedoutside the support wall 47, and thus at the same time that the PHhousing 40 is engaged in the housing body 21, the optical connector plug43 supported in this PH housing 40 and the optical connector ferrule 4 cof the MPO plug 4 b supported on the housing body 21 side are abutmentconnected.

With this optical connector, simply by pressing the optical connectorplug 43 into the plug accommodation grove 44 from the accommodationgroove opening 45, the optical connector plug 43 can be simplyaccommodated at a specified position within the PH housing 40, and thusthe assembly operability is significantly improved. Contrariwise, simplyby flexibly deforming the support claws 46 so as to part towards theoutside, the operation of extracting the optical connector plug 43 fromthe plug accommodation groove 44 can be easily carried out.

In addition, because of the small size of the optical connector plug 43,which is an optical connector ferrule defined by JIS C 5981, the PHhousing 40 that directly accommodates it can be significantlyminiaturized in comparison to the PH housing 5 (refer to FIG. 46) thataccommodates the MPO plug 4 a, and the printed board 2 in the plug-inunit 1 and the pitch of the arrangement of the PH housing 40 can besignificantly reduced, and thus the number of cores to which the opticalconnector can be applied can be increased.

Moreover, the PH housing of the optical connector of the presentinvention is not limited to the PH housing 40 shown in the aboveexamples, and can be adapted to any type of structure that supports anytype of optical connector ferrule not defined in JIS C 5981 and opticalconnector plugs such as the simplified MPO plug.

The PH housing 401 shown in FIG. 25 to FIG. 28 is installed on a printedboard 2 by a rivet part 55 described in detail below, and by insertingthe printed board 2 into the plug-in unit 1 (refer to FIG. 46 of therelated art), it is engaged into the BH housing 20 a. In addition, atthe same time as this engagement, the end of the MPO plug 4 a engaged inadvance in this PH housing 401 is inserted into the internal housing 21a, which is inserted into the plug accommodation hole 23 of the housingbody 21, to form an abutment connection with the MPO plug 4 b insertedinto the internal housing 21 a from the installation hole 30.

FIG. 26 is a perspective drawing showing the PH housing 401.

In FIG. 26, from both sides of the PH housing 401 (from top to bottom inFIG. 26), a pair of release claws 51 a and 51 b project to detachablyengage the housing body 21 (refer to FIG. 25) from the outside. Inaddition, as shown in FIG. 26, inside the PH housing 401, a sleeveshaped accommodating wall 52 is provided. On this accommodation wall 52,the MPO plug 4 a is inserted from the back (the left inner side in FIG.26) and engaged. In addition, at the end in the direction of insertion(the right front side in FIG. 26) of the PH housing 401 into the BHhousing 20 a, a double wall 53 projects.

As shown by the arrow in FIG. 25, when the PH housing 401 is insertedinto the BH housing 20 a, this double wall 53 is inserted towards aninsertion groove (not shown) maintained in the gap between the housingbody 21 and the internal housing 21 a that is accommodated within thishousing body 21, and therefore, the PH housing 401 is positioned towardthe BH housing 20 a. In addition, at this time, the double wall 52overlaps the outer surface of the internal housing 21 a, and reinforcesthe internal housing 21 a and the housing body 21. The PH housing 401inserted into the BH housing 20 a can be inserted up to the positionwhere the accommodation wall 52 (refer to FIG. 26) abuts the internalhousing 21 a.

When the MPO plug 4 a is inserted into the PH housing 401, the housingin the MPO plug 4 a (not shown) can be detachably engaged in the PHhousing 401. In addition, the MPO plug 4 a can be extracted by releasingthe engagement between the housing and the PH housing 401 by theextraction operation (extracting to the left side in FIG. 25) of thecoupling 4 d. Moreover, the MPO plug 4 b can also be detachably engagedwith the BH housing 20 a.

As shown in FIG. 27, a key groove 54 is formed in the accommodation wall52 of the PH housing 401, and by the key 4 e (refer to FIG. 25) of theMPO plug 4 a engaging this key groove 54, the MPO plug 4 a is positionedat a specified position within the PH housing 401. As shown in FIG. 25,the MPO plug 4 b inserted from the installation hole 30 side also has akey 4 e, and by this key 4 e engaging the key groove 21 b (refer to FIG.11) in the internal housing 21 a, it can be positioned at a specifiedlocation within the BH housing 20 a. In addition, when the PH housing401 is engaged with the BH housing 20 a, due to the positioning betweenthe PH housing 401 and the BH housing 20 a and the positioning due tothe engagement between the key 4 e of each MPO plug 4 a and 4 b and thekey groove 21 b of the internal housing 21 a, the MPO plugs 4 a and 4 bare positioned together, and the optical connector ferrules 4 c and 4 cof these MPO plugs 4 a and 4 b are positioned and abutment connected.When the PH housing 401 is correctly engaged in the BH housing 20 a, theguide pin 4 p of one optical connector ferrule 4 c can be smoothlyinserted and engaged in the guide pin hole of the other opticalconnector ferrule 4 c.

Moreover, reference numeral 54 a in FIG. 27 is an engaging claw thatdetachably engages the MPO plug 4 a.

The MPO plugs 4 a and 4 b have a built-in urging means (not shown) suchas a coil spring that urges the optical ferrules 4 c, and when the MPOplugs 4 a and 4 b are connected together, the urging force of theseurging means acts as an abutting force between the optical connectorferrules 4 c and 4 c, and thus the abutment force between the abutmentconnected optical connector ferrules 4 c and 4 c acts very efficiently.

As shown in FIG. 26, the rivet 55 that anchors the PH housing 401 to theprinted board 2 comprises a sleeve shaped rivet body 55 a made of asynthetic resin such as plastic and a rivet pin 55 b made of syntheticresin and inserted into the rivet body 55 a. As shown in FIG. 26 andFIG. 28, in the method using the rivet, first, the rivet body 55 ainserted into the rivet hole 57 of the PH housing 401 through the rivethole 56 in the printed board 2 reaches the deformation space 50 a (referto FIG. 28) of the PH housing 401. Next, the rivet hole 55 b is pressedinto the rivet body 55 a from the printed board 2 side (one end in theaxial direction of the rivet body 55 a), and when the end of this rivethole 55 b reaches the deformation part 55 c shaped by partitioning theother end of the rivet body 55 a in a plurality of locations makingslits in the axial direction, the projections 55 d projecting on theinside of each partitioned part of the deformation part 55 c arepressed, and the deformation part 55 c is deformed so as to spread outradially to the outside. Thereby, the PH housing 401 and the printedboard 2 are anchored by being held between the engaging projection 55 f(the flange part) projecting from the one end of the rivet body 55 a inthe radial direction and this deformation part 55 c.

When the rivet body 55 a communicates with the respective rivet holes 56and 57 of the printed board 2 and the PH housing 401, the engagingflanges 50 b of the PH housing 401 projecting in the vicinity of therivet holes 56 are engaged in advance in the rivet holes 56 of theprinted board 2, the communicating state of both rivet holes 56 and 57of the PH housing 401 side and the printed board 2 side is maintained,and thus the insertion operation of the rivet body 55 a is simple.

After the rivet body 55 a having the rivet pin 55 b, inserted in advanceonly to a depth such that the deformation part 55 c does not open,communicates with the rivet holes 56 and 57, the deformation part 55 cis pressed open by increasing the amount of pressure on the rivet pin 55b towards the PH housing 401, and thereby the printed board 2 and the PHhousing 401 can be anchored. At this time, at the work location, becausethe rivet part 55 a having the rivet pin 55 b inserted can be treated asone part, the operability of the anchoring is improved.

Moreover, the material of the rivet part 55 is not limited to resin. Awide selection of materials, such as metals, can be used, and the costcan be easily reduced by using inexpensive materials.

Therefore, in the PH housing 401, because the anchoring to the printedboard 2 is carried out with the rivet part 55, the anchoring operationcan simply be carried out by the insertion operation of the rivet body55 a and the pressure insertion operation of the rivet pin 55 b. Theoperating efficiency is greatly improved compared to anchoring by asmall-sized screw as disclosed in the related art. In addition, with theanchoring by the above-described screw, cost reduction is difficultbecause the screw is a special order part, and thus the processing ofthe PH housing 401 becomes special, which prevents cost reductions ofthe optical connector as a whole. If it is anchored by the rivet part55, the cost of the rivet part 55 can be easily reduced, and thus, thereduction of the cost of the optical connector as a whole is possiblebecause processing of the PH housing 401 is simple.

Furthermore, FIG. 29 and FIG. 30 show the PH housing 58 having a totalof four rivet holes 58 a and 58 b. As shown in FIG. 29, on the printedboard as well, there are a total of four rivet holes 56 a and 56 bcorresponding to these rivet holes 58 a and 58 b.

Engaging flanges 58 c project in the vicinity of the openings of therivet holes 58 a, and by engaging these engaging flanges 58 c in therivet holes 56 a of the printed board 2, the PH housing 58 can bepositioned at a specified position on the printed board 2.

As shown in FIG. 29 and FIG. 30, the rivet part 59 that communicateswith the rivet holes 56 a and 58 a provides a sleeve-shaped rivet body59 a and a rivet pin 59 b that is pressure inserted into this rivet body59 a from the one end in the axial direction, which is the back end inthe direction of insertion into these rivet holes 56 a and 58 a. Adeformation part 59 c is formed at the other end in the axial direction,which is the front end of the rivet body 59 a in the direction of theinsertion into the rivet holes 56 a and 58 a. Its end is inserted into adeformation space 58 d (expanded part) whose end opposite to theengaging flange 58 c of the rivet hole 58 a expands. In addition, whenthe rivet pin 59 b is pressure inserted into the rivet body 59 a, thedeformation part 59 c deforms so as to spread to the outside, andthereby the PH housing 58 and the printed board 2 are held between thisdeformation part 59 c and the engaging projection 59 d of the rivet body59 a.

The rivet holes 58 b pass through the bearing flange 58 e projectingtowards the backside (the left side in FIG. 30) from the PH housing 58.The rivet part 60 communicating with the rivet holes 56 b and 58 bprovide a sleeve-shaped rivet body 60 a and a rivet pin 60 b pressureinserted into the rivet body 60 a. In addition, the deformation part 60c, which is inserted from the printed board 2 side and passes throughthe rivet hole 58 b of the bearing flange 58 e to project to theopposite side of the bearing flange 58 e away from the printed board 2,is deformed by being pushed apart towards the outside by a rivet pin 60b that is pressure inserted into the rivet body 60 a, and thereby the PHhousing 58 and the printed board 2 are held between this deformed part60 c and the engaging projection 60 d of the rivet body 60 a.

Here, as shown in FIG. 29, the rivet hole 58 b has a diameter largerthan the rivet hole 58 a, and the rivet body 60 a of the rivet part 60that communicates with the rivet holes 56 a and 58 a has an externaldiameter larger than the rivet body 59 a of the rivet part 59communicating with the rivet holes 56 a and 58 a. In addition, the rivetbody 60 a of the rivet part 60 applied to the rivet holes 56 b and 58 bhas a length that is shorter than that of the rivet body 59 a of therivet part 59 using the rivet holes 56 a and 58 a. In this manner, thediameter and length dimensions of the rivet parts 59 and 60 are alteredas convenient to conform to the shape of the rivet holes 58 a and 58 b.When changing the dimensions of the diameter and length of the screws ofthe special order parts disclosed in the related art, labor is involvedin forming the screw groove, while in contrast the rivet parts 59 and 60can be easily made to correspond simply by forming them to the desiredshape using resin, and thus they obtain a wide applicability and can bereduced in cost. Furthermore, in the case of using screws, labor isinvolved because the screw holes formed on the PH housing 58 side mustbe changed according to the shape of the screw, whereas in contrast withthe rivet parts 59 and 60, it is only necessary to form of the rivetholes 58 a and 58 b for the insertion of the rivet parts 59 and 60 inthe PH housing 58, and thus the production efficiency of the PH housing58 is increased.

In addition, the supporting flange 58 e can be formed at a positionother than the back of the PH housing 58. For example, the supportingflanges can project at a plurality of locations on the PH housing 58,various rivet parts used in the rivet holes in each of these supportingflanges, and the PH housing 58 installed on the printed board 2. In thiscase, because rivet holes passing through the PH housing 58 areunnecessary, the design of the PH housing 58 is simplified. In addition,in the case that rivet holes are formed in the supporting flanges,because aligning the rivet hole shapes is simple and rivet parts havingidentical dimensions can be used, the processing efficiency of the rivetholes and the production efficiency of the rivet parts can be improvedand a greater cost reduction becomes possible.

In this manner, if the supporting flanges projecting from the PH housing58 or the rivets inside the PH housing 58 are formed, the PH housing 58can be anchored to the printed board by using rivet parts, so the designchanges are simple and great flexibility can be attained.

With the optical connector using this PH housing 58, because theanchoring force of the PH housing with respect to the printed board 2can be sufficiently guaranteed, even in the case that the resistanceforce produced during the engagement operation and the release operationbetween the PH housing 58 and the BH housing 20 a is high, there is noconcern about producing misalignment, etc., in the PH housing 58. Due tothis, even when generation of a large resistance force is anticipatedduring engagement and release, as when using large-sized PH housing andBH housing, for example, in connecting large sized MPO plugs having manycorresponding cores, the PH housing can be stably supported at aspecified position, and the operations of connecting and releasing theMPO plugs can be carried out smoothly.

Moreover, the formation position, size, number, etc., of rivet holes inthe printed board and the rivet holes in the PH housing, the shape ofthe deformation space for deforming the rivets, etc., are not limited tothose illustrated in the above-described embodiment, and can be alteredas appropriate.

As shown in FIG. 31, the fixed part 22 d can also be used with thisoptical connector.

As shown in FIG. 31 and FIG. 32, the BH housing 20 e provides a housingbody 21 and fixed part 22 d.

On the surface of the housing body 21 facing the PH housing 5 (the leftfront side in FIG. 31), a tapering surface 21 a that guides the PHhousing 5 into the plug accommodation hole 23 is formed in the vicinityof the plug accommodation hole 23. Moreover, as shown in FIG. 31,because the internal housing 21 a is inserted from the backplane 3 intothe housing 21 by the guide projections 21q, respectively projectingfrom the positioning projections 21 c on the four corners, beinginserted into the guide groove 21r formed in the housing body 21, theinsertion of the internal housing 21 a does not produce shifting and iscarried out smoothly. In addition, the internal housing 21 a can attaina stable accommodation state without producing shifting in any directionexcept the radial direction of the housing body 21 due to the guideprojection 21 q accommodated in the guide projection 21 p even afterbeing accommodated in the housing body 21. In addition, since theprojection-shaped positioning part 21s projecting from the engagingclaws 21 d on both sides of the internal housing 21 a is inserted intothe engaging groove 21 m in the housing body 21, it contributes topreventing shifting of the internal housing 21 a in the housing body 21.This positioning part 21 s will be explained in detail in FIGS. 34 and35 described below.

The whole fixed part 22 d is formed from a spring material, and providesa body 24 having an elongated frame shape, and a pair of flexible claws25 and 25 that project from both sides in the longitudinal direction(top to bottom in FIG. 31) of the body 24. The projection position ofthese flexible claws 25 and 25 conform to the pair of engaging holes 26and 26 formed on both sides opposite to the housing body 21 (there isalso an engaging hole 26 on the lower side of the housing body 21 inFIG. 31 and FIG. 32).

The flexible claws 25 and 25 have a flat spring shape, and the engagingclaws 27 project from the end 25 a in the projection direction of eachflexible claw 25 and 25. A constricted part 25 c formed more narrowlythan this end part 25 a by constrictions 25 b and 25 b formed on bothsurfaces is provided between this end part 25 a and the body 24.

As shown in FIG. 32, both flexible claws 25 and 25 engage engaging claws27 on the engaging parts 28 and 28 of the housing body 21 by passingthrough the installation hole 30 of the pack plane 3 and beingrespectively inserted into the engaging holes 26 and 26 of the housingbody 21 provided on the opposite side via the backplane 3.

The body 24 of the fixed part 22 d is larger than the installation hole30, and the plug insertion hole 29 in the center of the body 24 issmaller than the installation hole 30. As shown in FIG. 32, with theassembled BH housing, the backplane 3 can be gently held by a clampforce that allows sliding between the spring part 32 formed on the body24 of the fixed part 22 d and the housing body 21. The spring part 32connects both flexible claws 25 and 25, and is shaped by forming thebody 24 extending on both sides adjacent to the plug insertion hole 29,into an angled or curved shape (an angular shape in FIG. 31 and FIG.32), and the part that projects the furthest therefrom abuts thebackplane 3. Due to the tensile force of this spring part 32, a clampingforce is provided that holds the backplane 3 between the fixed part 22 dand the housing body 21. In addition, when the fixed part 22 d engagesthe housing body 21, the installation state of the housing body 21 isstabilized because the difference in the thickness dimension of thebackplane 3 is offset within the range of flexible deformation of thespring body 32.

In addition, the ends 25 a of both flexible claws 25 and 25 havedimensions approximately conforming to the vertical direction of theinstallation hole 30. As shown in FIG. 31, the constricted part 25 cnarrows by a step of about, for example, 0.4 mm on each side, or a totalof 0.8 mm for both sides, with respect to the flexible claw ends 25 aand 25 a. As shown in FIG. 32, when the flexible claws 25 and 25 areengaged in the engaging parts 28 and 28 of the housing body 21 by beinginserted into the installation hole 30, as shown in FIG. 33A and 33B,the constricted part 25 c is positioned in the installation hole 30,clearance is secured in the vicinity of the constricted part 25 c, andthe shifting of the flexible claws 25 and 25 within the installationhole 30 is permitted within the range of this clearance. Therefore, onthe BH housing 20 e installed on the backplane 3, floating is permittedin the range of possible movement of the flexible claws 25 and 25 withinthis installation hole 30.

For example, this clearance is guaranteed to be about C=1.00 mm orgreater in the horizontal direction (refer to FIG. 4), and d=1.60 mm inthe vertical direction. Within the range of this clearance, the flexibleclaws 25 and 25 can shift, and when either becomes large in comparisonto the fixed part 22 shown in FIG. 1, the floating range of the BHhousing 20 can be adequately set. The floating range of the BH housing20 e becomes remarkably large compared to the case of not forming aconstricted part 25 c on the flexible claws 25 and 25. Thereby, when thePH housing 5 is engaged in the BH housing 20 e by inserting the printedboard 2 into the plug-in unit 1 (refer to FIG. 46), the misalignmentbetween the PH housing 5 and the BH housing 20 e is offset by thefloating of the BH housing 2 e, and the engagement operability isimproved.

In FIG. 31, because the amount of tapering (dimension f-dimension g inFIG. 22B) of a tapered surface 21 a in the horizontal direction on bothsides of the housing body 21 is 1.275, when the PH housing 5 is insertedinto the plug accommodation hole 23, at most a misalignment ofapproximately 0.5 mm is tolerated in either the horizontal or verticaldirections between the BH housing 20 e and the PH housing 5, and for amisalignment within this range, the PH housing 5 can be inserted intothe BH housing 20 e, and there is a high flexibility with respect tomisalignment.

The amount of tapering can be selected according to convenience, and ofcourse can be larger than 1.275.

As shown in FIG. 31 and FIG. 33, the engaging part 28 of the housingbody 21 has a groove-shaped engaging concave part 28 a. This engagingconcave part 28 a is an angular grove shape, and each of the engagingclaws 27 of the flexible claws 25 and 25 engage on this engaging part 28so as to be inserted into the comer part of this engaging concave part28 a, and thus the inadvertent falling out or deformation of theengaging claws 27 is prevented. Thereby, even if the BH housing 20 efloats, the engaging claws 27 are not easily detached from the engagingparts 28. To the extent that the engaging claws 27 are not intentionallydeformed, the housing body 21 will not detach from the flexible claws 25and 25, and thereby, on the BH housing 20 e, the extraction resistanceforce is sufficiently guaranteed when the PH housing 5 is extracted.

In addition, the clearance in the vicinity of the flexible claws 25 and25 inserted in the installation hole 30 can be easily adjusted simply byadjusting the shape of the flexible claws 25 and 25, and thus thefloating range of the BH housing 20 e can be easily set. Thereby, theshape of the installation hole 30 can be made simple, and its formationoperability can be improved. Concretely, due to the indentations 25 bformed in the flexible claws 25, the shape of the constricted part canbe adjusted, and the desired clearance can be easily obtained. Moreover,the shape forming the indentations 25 b and 25 b on both sides of theconstricted part 25 c may be placed only on the projecting sides, and inthis manner the displacement limit of the BH housing 20 e in a specifieddirection can be set, and for example, can correspond to themisalignment of the PH housing 5 in a specified direction with respectto the BH housing 20 e.

In this manner, when sufficient clearance can be attained due to theshape of the indentations 25 b, the floating range of the BH housing 20e becomes large, the engagement operability of the PH housing 5 can beimproved, the misalignment, etc., of the pre-installed printed board 2with respect to the PH housing 5 can be broadly compensated, and theflexibility improved. Furthermore, with this optical connector, becausethe end part 25 a of a flexible claw is larger than the constricted part25 c, the engaging force with respect to the housing body 21 can beguaranteed, and inconveniences such as excessive shifting in the BHhousing 20 e due to the insufficiency of the force holding the backplane3 between the spring part 32 of the fixed part 22 d and the housing body21 can be prevented.

In addition, with this connector, because smooth movement of theinternal housing accommodated in the housing body 21 in the axialdirection of the housing body 21 is allowed, while shifting in any otherdirection is reliably repressed, the structure shown in FIG. 34 and FIG.35 can be used.

As shown in FIG. 34, the function of the engaging claws 212 d on bothsides (left to right in FIG. 34) of the internal housing 212, thepositioning projection 212 c and the external projection 212 pprojecting from both the top and bottom lower part (top to bottom inFIG. 34) is the same as the engaging claws, the positioning projection,and the external projection of the internal housing shown in FIG. 1.

FIG. 35 is a planar cross-sectional drawing showing the insertion stateof the internal housing 212 in the housing body 21.

In FIG. 35, the engaging claw 212 d provides a projecting part 212 fthat projects from the side of the internal housing 212 and a parallelpart 212 g that extends from this projection part 212 f along the axialdirection of the opening in the center of the internal housing 212, andis formed in the shape of an L. From the base of the parallel part 212 gnear the joint with the projecting part 212 f, a projection-shapedpositioning part 212 h projects towards the outside.

This engaging claw 21 d is made of resin, is integrally formed on theinternal housing 21, and is flexible.

In FIG. 35, the internal housing 212 is inserted into the housing body21 by movement in the direction of the arrow (from right to left in FIG.35). At this time, the engaging claw body 212 i at the end of thisparallel part 212 g is inserted into the engaging groove 212 e, and byriding over the partition wall 212 j projecting within this engaginggroove 212 e, is engaged in the engaging groove 212 e. The engagement ofthe engagement claw body 212 i with respect to the engagement groove 212e is not easily detached, and in addition, the positioning part 212 h inengaged by insertion into this engaging groove 212 e, and is not easilydetached from the engaging groove 212 e. Thereby, due to the positioningprojection 212 c, the engaging claws 212 d on both sides, and thepositioning parts 212 h, the internal housing 212 does not shift withinthe housing body 21 in any direction other than the direction axial tothe housing body 21, and is stabilized at a specified position.

In addition, compared to the case when only the engaging claw body 212 iabuts the inner surface of the housing body 21, inconveniences such asthe movement of the internal housing 21 in a direction axial to thehousing body 21 jamming midway do not occur because both the engagingclaw body 212 i and the positioning part 212 h slide to abut the innersurface of the housing body 21, and the movement becomes smooth. Thiscontributes to the stable movement of the internal housing 212 when theMPO plugs 4 a and 4 b are being connected, and contributes to increasingthe smoothness of the connection operation between the MPO plugs 4 a and4 b. Even after this connection, for example, in the case that apressure is applied from both sides of the MPO plugs 4 a and 4 b, thereis no catching midway in the BH housing in the direction that thepulling force acts, and because the movement is smooth, influence on theconnection state can be avoided.

In addition, the positioning part 212 h is also positioned in theengaging groove 212 e simply by positioning and inserting the engagingclaw 212 d into the engaging groove 212 e because the positioning part212 h is a projection that projects from the engaging claw 212 d. At thesame time, the engaging claw 212 d riding over the partitioning wall 212j engages in the engaging groove 212 e because the positioning part 212h is automatically engaged in the engaging groove 212 e, and thus evenin a narrow housing body 21, the positioning part 212 h can be easilyengaged in the engaging groove 212 e, and the insertion into theinternal housing 212 with respect with the housing body 21 can becarried out with high efficiency.

Moreover, the projection position of the positioning part 212 h in theengaging claw 212 d is not limited to the case of the parallel part 212g, and can be optionally selected as long as the position does notcontact the engagement claw body 212 i of the end of the engagement claw212 d.

In addition, the positioning unit is not limited to the shape thatengages the engaging groove 212 e, but, for example, any structure whoseshape has a projection inserted into the slit formed on one part of theengaging groove 212 e can be used.

As shown in FIG. 34, the BH housing 20 f is assembled when the backplaneis held between the housing body 21 and the fixed part 22 b. This BHhousing 20 f is stably engaged (FIG. 33A is a detailed drawing of thisengaged state) by the engaging claw 27 of the fixed part 22 b at the endof the flexible claw 25 entering the engaging concavity 28 a of theengaging part 28 of the housing body 21. In contrast, in the internalhousing 212 inserted in the housing body 21, there is no shifting, and astable accommodation state is attained. Because the ends of both MPOplugs 4 a and 4 b are connected by insertion into the internal housing212, the floating range of the internal housing 212 is important; in astate wherein shifting of the internal housing 212 in any directionexcept the axial direction of the housing body 21 is prevented, theamount of floating conforms to that of the BH housing 20 f, and theinternal housing 212 floats within a floating range set according to therelation between the flexible claws 25 and 25 and the installation hole30. Therefore, inconveniences such as the degradation of the insertionoperability of the MPO plugs 4 a and 4 b due to the shifting of theinternal housing 212 can be prevented, and the operation of connectingtogether the MPO plugs 4 a and 4 b by engaging the PH housing 5 in thehousing body 21 can be carried out reliably with high efficiency.

In addition, this optical connector can be applied to various the types,shapes, sizes of the MPO plugs 4 a and 4 b by appropriately selectingand using the internal housing 212 of the housing body 21. That is, whenthe shape, size, etc., of the particular end of the MPO plugs 4 a and 4b are altered, both plugs 4 a and 4 b should be positioned accordingly,and appropriate ones must be selected and used. However, with theinternal housing according to the present invention, even if the designof the internal housing itself is altered, simply by altering thedesigns of the engaging claws 212 d and the positioning part 212 h,there will be no shifting with respect to the housing body 21, and astable insertion state therein can be easily attained.

Thereby, the optical connector according to the present inventionattains a high flexibility with respect to the optical connector plugs,and, for example, can be applied to connections between various types ofoptical connector plugs besides MPO plugs, and connections betweendifferent types of optical connector plugs.

Second Embodiment

As shown in FIG. 36, the housing body 213 that forms the BH housing 20 gis formed in a sleeve-shape from a synthetic resin such as plastic, andis identical to the housing body shown in FIG. 1 on the point ofproviding a plug accommodation hole 23 that accommodates the insertedMPO plugs 4 a and 4 b, and the point of accommodating the internalhousing 21 a in the plug accommodation hole 23, but differs from thehousing body 21 on the point of providing an engaging part 213 a havinga different shape from that of the engaging part 28 of the housing body21.

The fixed part 22 e is entirely formed of a synthetic resin such asplastic and having a rectangular shaped frame, and provides a body 224and a pair of flexible claws 225 and 225 that project from both sides ofthe body 224. The separation distance between these flexible claws 225and 225 agrees with the separation distance between the pair of engagingparts 213 a and 312 a formed on both sides opposite to the housing body213 (there is also an engaging part 213 a on the bottom side of thehousing body 213 in FIG. 36 and FIG. 37). In addition, both flexibleclaws 225 and 225 are formed at a position facing the plug insertionhole 229, and the outer edge 224 a of both lengthwise ends of the body224 project towards the outside of the flexible claws 225 and 225.

In FIG. 37, by insertion into the installation hole 30 of the backplane3, the engaging claws 227 of both flexible claws 225 and 225 engagerespectively on both engaging parts 213 a and 213 a of the housing body213 set on the opposite side via the backplane 3. Here, the separationdistance between both engaging claws 227 and 227 is somewhat smallerthan the separation distance between both engaging parts 213 a and 213a, and thus the housing body 213 becomes held between both engagingclaws 227 and 227, and the engaging claws 227 cannot be easily detachedfrom the engaging part 213 a.

Moreover, as shown in FIG. 38, because an inclined surface 213 b isformed on the engaging parts 213 a and 213 a, the flexible claws 225ride over the inclined surface 213 b due to their flexible deformation,and can be easily engaged with the engaging parts 213 a simply byinserting the engaging claws 227.

As shown in FIG. 36, the installation hole 30 is rectangular, andextends in the form of a slit along the backplane 3. The external shapeof the body 224 of the fixed part 22 e is larger than the installationhole 30, and the plug installation hole 229 in the center of the body224 is smaller than the installation hole 30. As shown in FIG. 37, withthe assembled BH housing 20 g, the backplane is gently held between thehousing body 213 and the body 224 by a clamping force that allowssliding. At this time, the entire body 224, including the external edges224 a and 224 b, abuts the backplane 3.

In addition, the clearance is ensured in the vicinity of the flexibleclaws 225 and 225 inserted in the installation hole 30, and displacementof the flexible claws 225 and 225 in the installation hole 30 withinthis range of clearance is permitted. Therefore, on the BH housing 20 ginstalled on the backplane 3, the flexible claws 225 and 225 can floatin this installation hole 30 within the range of possible movement. Forexample, a clearance of c=0.34 mm in the horizontal direction (left toright in FIG. 39) and d=1.60 mm in the vertical direction (top to bottomin FIG. 39) is guaranteed, and the flexible claws 225 and 225 can bedisplaced within the range of this clearance; thus, the floating rangeof the BH housing 20 g is set. Thereby, when the printed board 2 isinserted into the plug-in unit (refer to FIG. 46) and the PH housing 5is engaged in the BH housing 20 g, the misalignment between the PHhousing 5 and the BH housing 20 g is offset by the floating of the BHhousing 20 g, and thus engagement operability is improved. At this time,the entire body 224, including the outer edges 224 a and 224 b, abutsthe backplane 3, and thus a large supporting surface area can beguaranteed. Furthermore, the supporting surface 224 c of the body 224that abuts the backplane extends so as to hold the flexible claws 225and 225, and thus the floating of the BH housing 20 is stabilized,excessive shifting can be repressed, and the engagement operability ofthe PH housing 5 and the BH housing 20 can be improved.

When this BH housing 20 g is assembled in the backplane 3, the pair ofengaging claws 227 are engaged in the engaging parts 213 a and 213 aexposed on both sides of the housing body 213 from the outside of thehousing body 213, and thus the engagement between the engaging claws 227and engagement parts 213 can be carried out visually, and theoperability is increased.

In addition, simply by adjusting the shape of the flexible claws 225 and225 (thickness, etc.), the clearance in the vicinity of the flexibleclaws 225 and 225 inserted in the installation hole 30 can be adjustedeasily, and thus the floating range of the BH housing 20 g can be easilyset. Thereby, the shape of the installation hole 30 can be simple, andthe formation operation improved.

Moreover, the present invention is not limited to this embodiment, andfor example, the shape, etc., of the engaging part of the housing bodycan be altered as appropriate.

Third Embodiment

As shown in FIG. 40 and FIG. 41, the BH housing 20 i is structured toprovide a housing body 101 that accommodates the inner housing 21 a andan installation part 102 that is attached to the outside of this housingbody 101, and is installed at the desired position by a pair of flexibleclaws 108 and 108 that project from the installation part 102 beingengaged with the installation hole 30 (refer to FIG. 40) in thebackplane 3 of the plug-in unit 1 (refer to FIG. 46).

The housing body 101 is formed in a sleeve shape from a synthetic resinsuch as plastic, and the accommodates the internal housing 21 a in aplug accommodation hole 103 that passes through its center.

The entire installation part 102 is formed from a tensile material, andas shown in FIG. 41, a body 104 mounted and anchored to the housing body101 from the outside is provided. As shown in FIG. 40 and FIG. 41, thisbody 104 has a gate shape, and by both flange parts 107 and 107 onopposite sides engaging between the projections 105 and 106 that projecton the side surface of the housing body 101, it is stably anchoredwithout misalignment on the housing body 101, and thereby this BHhousing 20 i is assembled.

Flexible claws 108 project from each flange part 107 and 107. Anengaging claw 109 projects from the end of these flexible claws 108 and108 that project from both flange parts 107 and 107.

FIG. 42 is a perspective drawing viewing the installation part 102 fromthe side of the flexible claws 108.

In FIG. 42, the separation distance between both flexible claws 108 and108 is smaller than the separation distance between both flange parts107 and 107 of the body 104. The engaging claws 109 of each flexibleclaw 108 and 108 project from both flexible claws 108 and 108 towardsthe outside. A supporting wall 110 is formed between the body 104 andthe flexible claws 108 and 108. This supporting wall 110 holds thebackplane 3 between the engaging claws 109. The flexible claws 108 andthe supporting wall 110 are made integral to the housing body 102 byanchoring the installation part 102 in the housing body 101.

FIG. 43 is a planar drawing showing the BH housing 20 i installed in thebackplane 3, and FIG. 44 is a frontal drawing showing the installationhole 30 in the backplane 3.

As shown in FIG. 43, when both flexible claws 108 and 108 are insertedin the installation hole 30, the engaging claws 109 engage the backplane3 on both sides of the installation hole 30, the backplane 3 is heldbetween the engaging claws 109 and the supporting wall 110, and the BHhousing 20 i can be installed of the backplane 3. The holding force onthe backplane 3 between the engaging claws 109 and the supporting wall110 is an amount allowing sliding of the engaging claws 109 and thesupporting wall 110 with respect to the backplane 3. In addition,between both flexible claws 108 and 108, the groove-shaped pluginsertion part 112, having a size that allows passage of the MPO plug 4b inserted from outside the plug-in unit 1 (refer to FIG. 46) via theinstallation hole 30 (refer to FIG. 40), is secured. This plug insertionpart 112 communicates with the plug installation hole 103 (refer to FIG.40 and FIG. 41) of the housing body 101, and thus the MPO plug 4 binserted into the plug insertion part 112 from outside the backplane 3(left side in FIG. 43) can be inserted into the plug installation hole103.

As shown in FIG. 44, the installation hole 30 is rectangular, and has asize that guarantees the clearance in the vicinity of both insertedflexible claws 108 and 108. This clearance can be maintained, forexample, in the horizontal direction (left to right in FIG. 44) atc=0.34 mm and in the vertical direction (top to bottom in FIG. 44) atd=1.60 mm. The flexible claws 108 and 108 can float within this range,and thus floating of the BH housing 20 i is allowed.

When the PH housing 5 is engaged in the BH housing 20 i by inserting theprinted board 2 into the plug-in unit 1 (refer to FIG. 46), the MPO plug4 a on the PH housing 5 side is inserted into the internal housing 21 awithin the housing body 101, and contacts the MPO plug 4 b inserted intothe housing body 101 via the installation hole 30. At this time, becausemisalignment between the PH housing 5 and the BH housing 20 i is offsetby the floating of the BH housing 20 i, the operability of the PHhousing 5 engaging in the BH housing 20 i is improved.

In installing this BH housing 20 i into the backplane 3, inserting theflexible claws 108 and 108 into the installation hole 30, and engagingthe engaging claws 109 and 109 into the backplane 3, does not requirework from both sides of the backplane 3 because it is only necessary toassemble the BH housing 20 i by attaching the installation part 102 onthe housing body 101, and thus the installation operability is greatlyimproved. In addition, because the BH housing 20 i can be installed byworking only on the inside of the plug-in unit 1 (refer to FIG. 46), aworking space adjacent to the backplane 3 on the outside of the plug-inunit 1 is not necessary, and this is advantageous in the case ofapplication in, for example, the wall of a building. Moreover, theinternal housing 21 a can be accommodated in the housing body 101 inadvance.

In addition, because the clearance in the vicinity of the flexible claws108 and 108 inserted into the installation hole 30 can be adjustedsimply by adjusting the shape of the flexible claws 108 and 108, and thefloating range of the BH housing 20 i can be easily set, the shape ofthe installation hole 30 can be simple, and thus the formationoperability is improved.

Furthermore, since pins are not used, the number of parts is reduced,and thus the effect of cost reduction can be attained.

As shown in FIG. 45, by integrally forming the sleeve shaped housingbody 100 from resin, the ends of a pair of integrally formed projectingflexible claws 110 are engaged with the backplane 3 by being inserted inthe installation hole 30, and the backplane 3 is held between the endsof the flexible claws 100 a and the supporting wall 100 b (the ends inthe axial direction of the housing body 100), and thereby a structurefor installation at the desired position on the backplane 3 can be used.Here, the housing body 100 that accommodates the internal housing 21 aitself forms the BH housing 20 j. In this optical connector as well, dueto the clearance secured in the vicinity of the pair of flexible claws100 a inserted in the insertion hole 30, naturally the floating range ofthe BH housing 20 j is guaranteed. Because the optical connector havingthis structure does not need an installation part, there are theadvantages that, for example, the cost can be lowered, and the assemblytime can be reduced.

Moreover, the present invention is not limited to any of theabove-described embodiments, and for example, the shapes, materials,etc., of the housing body, the internal housing, the PH housing, thefixed part, the installation part, etc., can be altered as appropriate.

Optical fibers connected by the optical connector according to thepresent invention are mainly single mode, but it can be adapted tomulti-mode optical fibers. In addition, this optical connector can beapplied to single core, four cores, 8 cores, etc., or any number ofcores.

Considering anti-corrosiveness and flexibility, stainless steel, forexample, could also be used as a material for the fixed part.

A PPS (polyphenylenesulfide) resin, for example, can be advantageouslyused as a material for the housings (BH housing, PH housing, internalhousing) that form the optical connector.

Up until this point, the structure of an optical connector providing aBH connector having a structure wherein the MPO plugs 4 a and 4 b arepositioned so as to be connectable by abutment using an internal housingaccommodated inside a housing body, but the optical connector of thepresent invention is not limited thereto, and for example, a structurewherein an MPO plugs 4 a and 4 b that are directly positioned by ahousing body that does not provide an internal housing can be used. Inthis case, a structure wherein the housing body of the BH housingfunctions as an adapter that positions the MP plugs inserted from bothsides can be used.

What is claimed is:
 1. An optical connector having a housing body and afixed part disposed opposite each other on the front and back sides of abackplane and installed so as so hold said backplane therebetween, andconnecting an optical connector plug inserted into said housing body viaan installation hole in said backplane and another optical connectorplug inserted into said housing body from the direction opposite to thatof said optical connector plug, wherein: said fixed part provides a pluginsertion hole into which said optical connector plug is inserted andflexible claws that are positioned on opposite sides of said pluginsertion hole and engage by being inserted into said housing body; andfurther wherein: said flexible claws engage said housing body via saidinstallation hole of said backplane, and thereby said housing body andsaid fixed part are installed so as to hold said backplane, and saidplug insertion hole communicates with said installation hole and saidhousing body; and wherein: said fixed part (22 a-22 d) provides: a pluginsertion hole (29) into which said optical connector plug (4 b) isinserted; flexible claws (25) that are disposed on opposite sides ofsaid plug insertion hole (29) and inserted into said housing body (21);and a spring part (31, 32, 34) that is disposed on opposite sides ofsaid plug insertion hole (29) and abuts said backplane; and wherein said flexible claws (25) engage said housing body (21) via saidinstallation hole (30), said housing body (21) and said fixed part (22a-22 e) are installed hole (30), said housing body (21) and said fixedpart (22 a-22 e) are installed so as to hold said backplane (3) betweensaid housing body (21) and said spring part (31, 32, 34), and therebysaid plug insertion hole (29) communicates with said installation hole(30) and said housing body (21).
 2. An optical connector having ahousing body and a fixed part disposed opposite each other on the frontand back sides of a backplane and installed so as so hold said backplanetherebetween, and connecting an optical connector plug inserted intosaid housing body via an installation hole in said backplane and anotheroptical connector plug inserted into said housing body from thedirection opposite to that of said optical connector plug, wherein: saidfixed part provides a plug insertion hole into which said opticalconnector plug is inserted and flexible claws that are positioned onopposite sides of said plug insertion hole and engage by being insertedinto said housing body; and further wherein: said flexible claws engagesaid housing body via said installation hole of said backplane, andthereby said housing body and said fixed part are installed so as tohold said backplane, and said plug insertion hole communicates with saidinstallation hole and said housing body; said optical connectorcharacterized in being a structure wherein: a printed board housing (5,36, 40, 58, 401) installed on a printed board (2) freely movably withrespect to said backplane (3) detachably engages said housing body (21,213), and thereby optical connector plug (4 a) supported in said printedboard housing (5, 36, 40, 58, 401) is inserted into said housing body(21, 213) and is connected to said optical connector plug (4 b) that isinserted into said housing body (21, 213) via the installation hole(30).
 3. An optical connector according to claim 2 wherein: said housingbody (21) has a sleeve shape, and accommodates therein an internalhousing (211) that accommodates, positions, and supports both of saidconnected optical connector plugs (4 a, 4 b), and a projecting wall (21e) engages said housing body (21) on the side of said internal housing(211); and a double wall (36 a) provided on said printed board housing(36) overlaps said projecting wall (21 e) when said printed boardhousing (36) engages said housing body (21); and lateral pressure actingin a direction different from the insertion and extraction direction ofthe optical connector plugs (4 a, 4 b) with respect to said internalhousing is borne by being diffused by said double wall (36 a) and saidhousing body (21) due to the engagement of said projecting wall (21 e)and double wall (36 a).
 4. An optical connector according to claim 2,wherein: said housing body (21) has a sleeve shape, and accommodatestherein an internal housing (211) that accommodates, positions, andsupports both of said connected optical connector plugs (4 a, 4 b), anda projecting wall (21 e) engages said housing body (21) on the side ofsaid internal housing; and said printed housing (36) provides a bearingwall (36 c) that engages the inside or the outside of said housing body(21), and said bearing wall (36 c) restricts the deformation of saidhousing body (21).
 5. An optical connector according to claim 2,wherein: plug accommodation grooves (44) are provided that accommodatesaid optical connector plugs (43) in said printed board housing (40);and further wherein: said plug accommodation grooves (44) have: anaccommodation groove opening (45) in the backside of said printed boardhousing (40) in the direction of engagement to said housing body (21);and flexibly deformable supporting claws (46) that project to engage andsupport an optical connector plug accommodated within said plugaccommodation grooves (44) adjacent to said accommodation groove opening(45) and further wherein: said optical connector plugs (43) areaccommodated and supported at a desired position within said plugaccommodation grooves (44) by flexibly deforming said supporting claws(46) while pressing said optical connector plugs (43) into said plugaccommodation grooves (44).
 6. An optical connector according to claim 5wherein the optical connector plugs (43) supported in the printed boardhousing (40) are optical connector ferrules (43) that terminate anoptical fiber (48) in an abutment connectable manner.
 7. An opticalconnector according to claim 2, wherein: said printed board (2) and saidprinted board housing (401, 58) are anchored by rivet parts (55, 59, 60)that communicate with rivet holes (56, 56 a, 56 b) that pass through theprinted board (2) and the rivet holes (57, 58 a, 58 b) formed in saidprinted board housing (401, 58).
 8. An optical connector according toclaim 7 wherein: said rivet parts (55, 59, 60) provide: sleeve shapedrivet bodies (55 a, 59 a, 60 a) that communicate with the rivet holes(56, 56 a, 56 b) of said printed board (2) and the rivet holes (57, 58a, 58 b) of the printed board housing (401, 58); and rivet pins (55 b,59 b, 60 b) that are inserted from one end of said rivet bodies (55 a,59 a, 60 a) in the axial direction, and deform so as to spread laterallyby force a deformation part (55 c, 59 c, 60 c) formed on the other endof said rivet body (55 a, 59 a, 60 a) in the axial direction byadjusting the amount of pressure on the other end of said rivet bodies(55 a, 59 a, 60 a) in the axial direction; and wherein: said printedboard (2) and said printed board housing (401, 58) are stabilized bybeing held between engaging projections (55 f, 59 d, 60 d) projectingfrom one end of said rivet body (55 a, 59 a, 60 a) in the axialdirection and said deformation part (55 c, 59 c, 60 c) deformed by saidrivet pin (55 b, 59 b, 60 b).
 9. An optical connector according to claim7 wherein: rivet holes (58 b) are formed on bearing flanges (58 e)projecting from the side of said printed board housing (58).
 10. Anoptical connector having a housing body and a fixed part disposedopposite each other on the front and back sides of a backplane andinstalled so as so hold said backplane therebetween, and connecting anoptical connector plug inserted into said housing body via aninstallation hole in said backplane and another optical connector pluginserted into said housing body from the direction opposite to that ofsaid optical connector plug, wherein: said fixed part provides a pluginsertion hole into which said optical connector plug is inserted andflexible claws that are positioned on opposite sides of said pluginsertion hole and engage by being inserted into said housing body; andfurther wherein:  said flexible claws engage said housing body via saidinstallation hole of said backplane, and thereby said housing body andsaid fixed part are installed so as to hold said backplane, and saidplug insertion hole communicates with said installation hole and saidhousing body; and wherein: said fixed part (22 d) provides: a body (24)having a plug insertion hole (29) into which said optical connector plug(4 a) is inserted; and flexible claws (25) that project from said body(24) on both sides of said plug insertion hole (29) and engage byinsertion into said housing body (21) via said installation hole (30);and is structured so that:  said housing body (21) and said fixed part(22 d) are installed by holding said backplane (3) between said housingbody (21) and said body (24), and said plug insertion hole (29)communicates with said installation hole (30) and said housing body (21)by engaging said flexible claws (25) in said housing body (21) via saidinstallation hole (30) of said backplane (3); and further wherein: saidflexible claws (25) provide a constricted part (25 c) having across-sectional shape that is narrower than said end part (25 a) due toindentations (25 b) formed on the sides between the end (25 a) engagingwith said housing body (21) and said body (24), and wherein:  when saidflexible claws (25) are inserted in said installation hole (30), saidconstricted part (25 c) is positioned in said installation hole (30),and due to a clearance maintained in the vicinity of said constrictedpart (25 c), the displacing of said flexible claws (25) is allowedwithin said installation hole (30).
 11. An optical connector having ahousing body and a fixed part disposed opposite each other on the frontand back sides of a backplane and installed so as so hold said backplanetherebetween, and connecting an optical connector plug inserted intosaid housing body via an installation hole in said backplane and anotheroptical connector plug inserted into said housing body from thedirection opposite to that of said optical connector plug, wherein: saidfixed part provides a plug insertion hole into which said opticalconnector plug is inserted and flexible claws that are positioned onopposite sides of said plug insertion hole and engage by being insertedinto said housing body; and further wherein: said flexible claws engagesaid housing body via said installation hole of said backplane, andthereby said housing body and said fixed part are installed so as tohold said backplane, and said plug insertion hole communicates with saidinstallation hole and said housing body; and wherein: said housing body(21) has a sleeve shape into which a sleeve-shaped internal housing (21a, 212) is inserted, said internal housing (21 a, 212) having insertedand connectably positioned therein the ends of respective opticalconnector plugs (4 a, 4 b); and further providing: engaging claws (21 d,212 d) that engage the engaging grooves (21, 212 e) formed inside saidhousing body (21) when said internal housing (21 a, 212) is inserted insaid housing body (21); and positioning parts (21 s, 212 h) projectingfrom these engaging claws (21 d, 212 d) or adjacent thereto thatposition said internal housing (21 a, 212) into said housing body (21)by insertion into the engaging grooves (21 m, 212 e) when said engagingclaws (21 d, 212 d) are inserted into said engaging grooves (21 m, 212e).
 12. An optical connector according to claim 11 wherein: saidengaging claws (212 d) provide: a projecting part (212 f) that projectsfrom the side of said internal housing (212); and a parallel part (212g) that extends along the radial direction of said internal housing(212) from said projecting part (212 f); and wherein: said positioningpart (212 h) is a projection that projects from said parallel part (212g) adjacent to said projection part (212 f).
 13. An optical connectorhaving a housing body and a fixed part disposed opposite each other onthe front and back sides of a backplane and installed so as so hold saidbackplane therebetween, and connecting an optical connector pluginserted into said housing body via an installation hole in saidbackplane and another optical connector plug inserted into said housingbody from the direction opposite to that of said optical connector plug,wherein: said fixed part provides a plug insertion hole into which saidoptical connector plug is inserted and flexible claws that arepositioned on opposite sides of said plug insertion hole and engage bybeing inserted into said housing body; and further wherein: saidflexible claws engage said housing body via said installation hole ofsaid backplane, and thereby said housing body and said fixed part areinstalled so as to hold said backplane, and said plug insertion holecommunicates with said installation hole and said housing body wherein: said fixed part (22 e) provides: a plug insertion hole (229) into whichsaid optical connector lug (4 b) is inserted; and a pair of flexibleclaws (225) disposed on opposite sides of said plug insertion hole (229)and engaging the side of said housing body (213); and wherein each ofsaid flexible claws (225) provides engaging claws (227) that projecttowards the flexible claws (225) on the opposing side; the engaging part(213 a) is engaged by said engaging claw (227) from the outside on bothsides of said housing body (213); and the engaging claws (227) of bothflexible claws (225) inserted in said installation hole (30)respectfully engaging the engaging part (213 a) of said housing body(213), and thereby said housing body (213) and said fixed part (22 e)are installed so as to hold said backplane (3), and said plug insertionhole (229) communicates with said installation hole (30) and saidhousing body (213).